US7442944B2ExpiredUtilityPatentIndex 79
Ion beam implant current, spot width and position tuning
Assignee: VARIAN SEMICONDUCTOR EQUIPMENTPriority: Oct 7, 2004Filed: Oct 7, 2004Granted: Oct 28, 2008
Est. expiryOct 7, 2024(expired)· nominal 20-yr term from priority
Inventors:CHANG SHENGWUCUCCHETTI ANTONELLADZENGELESKI JOSEPH PGIBILARO GREGORY RMOLLICA ROSARIONORRIS GREGG AOLSON JOSEPH CWELSCH MARIE J
H01J 2237/31703H01J 37/3171H01J 2237/24542H01J 2237/30461H01J 37/30H01J 37/317H01J 37/36
79
PatentIndex Score
9
Cited by
15
References
25
Claims
Abstract
An ion beam tuning method, system and program product for tuning an ion implanter system are disclosed. The invention obtains an ion beam profile of the ion beam by, for example, scanning the ion beam across a profiler that is within an implant chamber; and tunes the ion implanter system to maximize an estimated implant current based on the ion beam profile to simultaneously optimize total ion beam current and ion beam spot width, and maximize implant current. In addition, the tuning can also position the ion beam along a desired ion beam path based on the feedback of the spot beam center, which improves ion implanter system productivity and performance by reducing ion beam setup time and provides repeatable beam angle performance for each ion beam over many setups.
Claims
exact text as granted — not AI-modified1. A method for tuning an ion beam in an ion implanter system, the method comprising the steps of:
obtaining an ion beam profile of the ion beam; and
tuning the ion implanter system to maximize an estimated implant current based on the ion beam profile to simultaneously optimize total ion beam current and ion beam spot width, and maximize implant current.
2. The method of claim 1 , further comprising the steps of:
estimating the implant current based on the ion beam profile; and
determining the ion beam spot width and a spot beam center based on the ion beam profile.
3. The method of claim 2 , wherein the tuning step further includes adjusting implanter system elements including at least one of a limiting aperture, a mass slit, a manipulator, a source magnet, a pre-analyzing magnet, a charge-selecting magnet and an analyzer magnet to position the ion beam along a desired ion beam path based on the feedback of the spot beam center.
4. The method of claim 1 , wherein the estimated implant current is determined according to:
I
est
=
I
beam
×
tar
width
tar
width
+
(
m
+
n
)
W
/
2
+
a
where I est is estimated implant current, I beam is the total ion beam current, tar width is the target width exposed to the ion beam, m and n are constants, a is a distance the target is to a dose control Faraday cup, and W is the ion beam spot width.
5. The method of claim 1 , wherein the tuning step includes adjusting at least one of: a gas flow; an ion source; a source magnet; a source bias voltage; a suppression electrode; an extraction electrode; a manipulator motor; a pre-analyzing magnet; a charge-selecting magnet; an analyzer magnet; an accelerator focus electrode; an accelerator suppression electrode; a mass slit; a pre-scan suppression electrode; horizontal scan plates; a post-scan suppression electrode; a nitrogen (N 2 ) bleed; a corrector magnet; a limiting aperture of the ion implanter system.
6. The method of claim 1 , wherein the obtaining step includes scanning the ion beam across a profiler that is within an implant chamber.
7. The method of claim 6 , wherein the scanning step includes using a beam scanner to scan the ion beam, the beam scanner selected from one of horizontal scan plates, a corrector magnet and a magnetic scanner of the ion implanter system.
8. The method of claim 7 , further comprising the step of calibrating the beam scanner to position the ion beam to intersect the profiler.
9. The method of claim 1 , wherein the scanning step includes positioning the profiler in substantially a center of the implant chamber.
10. The method of claim 1 , wherein the profiler includes a Faraday cup.
11. A system for tuning an ion beam in an ion implanter system, the system comprising:
means for obtaining an ion beam profile of the ion beam; and
means for tuning the ion implanter system to maximize an estimated implant current based on the ion beam profile to simultaneously optimize total ion beam current and ion beam spot width, and maximize implant current.
12. The system of claim 11 , wherein the profiling means further functions to:
determine an ion beam profile,
estimate the implant current based on the ion beam profile, and
determine the ion beam spot width and a spot beam center based on the ion beam profile.
13. The system of claim 11 , wherein the tuning means further includes means for adjusting implanter system elements including at least one of a limiting aperture, a mass slit, a manipulator, a source magnet, a pre-analyzing magnet, a charge-selecting magnet and an analyzer magnet to position the ion beam along a desired ion beam path based on the feedback of the spot beam center.
14. The system of claim 11 , wherein the estimated implant current is determined according to:
I
est
=
I
beam
×
tar
width
tar
width
+
(
m
+
n
)
W
/
2
+
a
where I est is estimated implant current, I beam is the total ion beam current, tar width is the target width exposed to the ion beam, m and n are constants, a is a distance the target is to a dose control Faraday cup, and W is the ion beam spot width.
15. The system of claim 11 , wherein the obtaining means includes means for controlling scanning of an ion beam across a means for profiling that is within an implant chamber.
16. The system of claim 15 , wherein the profiling means is positioned substantially at a center of the implant chamber.
17. A computer program product comprising a computer useable medium having computer readable program code embodied therein for tuning an ion beam in an ion implanter system, the program product comprising:
program code configured to obtain an ion beam profile of the ion beam; and
program code configured to tune the ion implanter system to maximize an estimated implant current based on the ion beam profile to simultaneously optimize total ion beam current and ion beam spot width, and maximize implant current.
18. The program product of claim 17 , wherein feedback includes an ion beam profile, and further comprising program code configured to estimate the implant current based on the ion beam profile; and program code configured to determine the ion beam spot width and the spot beam center based on the ion beam profile.
19. The program product of claim 18 , further comprising the program code configured to adjust implanter system elements including at least one of a limiting aperture, a mass slit, a manipulator, a source magnet, a pre-analyzing magnet, a charge-selecting magnet and an analyzer magnet to position the ion beam along a desired ion beam path based on the feedback of the spot beam center.
20. The program product of claim 17 , wherein the estimated implant current is determined according to:
I
est
=
I
beam
×
tar
width
tar
width
+
(
m
+
n
)
W
/
2
+
a
where I est is estimated implant current, I beam is the total ion beam current, tar width is the target width exposed to the ion beam, m and n are constants, a is a distance the target is to a dose control Faraday cup, and W is the ion beam spot width.
21. The program product of claim 17 , wherein the tuning program code adjusts at least one of: a gas flow; an ion source; a source magnet; a source bias voltage; a suppression electrode; an extraction electrode; a manipulator motor; a pre-analyzing magnet; a charge-selecting magnet; an analyzer magnet; an accelerator focus electrode; an accelerator suppression electrode; a mass slit; a pre-scan suppression electrode; horizontal scan plates; a post-scan suppression electrode; a nitrogen (N 2 ) bleed; a corrector magnet; a limiting aperture of the ion implanter system.
22. The program product of claim 17 , wherein the obtaining program code includes program code configured to control scanning of the ion beam across a profiler that is within an implant chamber.
23. The program product of claim 22 , wherein the scanning control program code controls a beam scanner to scan the ion beam, the beam scanner selected from one of horizontal scan plates, a corrector magnet and a magnetic scanner of the ion implanter system.
24. The program product of claim 23 , further comprising the program code configured to calibrate the beam scanner to position the ion beam to intersect the profiler.
25. The program product of claim 22 , wherein the scanning control program code positions the profiler in substantially a center of the implant chamber.Cited by (0)
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